1. Field of Invention
This invention relates generally to devices for use in medical procedures, and more particularly, relates to steerable wire guides used separately or in conjunction with catheters or endoscopes. Specifically, this invention relates to an improved steerable wire guide including interlocking movable component access to hard to reach internal anatomy of a patient.
2. Related Technology
Wire guides are used in various medical procedures involving the gastrointestinal system, including the pancreatobiliary system (i.e., the biliary tree), the stomach, and the esophagus. Wire guides can be long, slender, relatively flexible wires used to access a patient's narrow passageway during minimally invasive medical procedures. Wire guides can be cumbersome as well as requiring constant, delicate manipulation by the treating physician because of the length of the wire guide.
Alternately, wire guides can also be described as elongated flexible members used to provide a path along which another medical device can be moved. The path provided by the wire guide can be used to navigate an alternate medical device, such as a catheter, through a body vessel. In this configuration, the wire guide can provide an established path for inserting other devices, eliminating the need for performing delicate navigation procedures for each device passed through the vessel. The use of wire guides to define such a path is known in the art.
Wire guides must have the ability to be maintained in a stationary position during various medical procedures. In operation, the wire guide is navigated through a body vessel to the desired target location. Once positioned within the body vessel, a second medical device, frequently a cannula such as a catheter can be placed over the wire guide and transported to the desired target location for treatment.
The operator of the wire guide must navigate the wire guide through the body vessel. Often, the body vessel forms a torturous path as a result of natural bends or curves in the body vessel or in the alternative, unnatural impediments, such as tumors or build-ups, which may also exist. The existence of this torturous path makes the navigation of the wire guide difficult. For example, the presence of an impediment may block the wire guide from navigating further into the vessel to reach the target or repair location.
As a result of the complexity of the above-described procedures, physicians often need the assistance of another person to secure the wire guide in addition to any additional medical devices used. Consequently, the physician's assistant must divert his or her attention from his or her primary responsibilities such as checking the patient's vital signs, checking monitors for relevant information and carrying out other tasks to assisting with maintaining the stability of the steerable wire guide.
The related art includes several examples of wire guides having a straight flexible tip and an elongated body portion intended to aid in the navigation of the wire guide. The presence of the straight flexible tip, however, may in fact make navigation more difficult. For example, upon encountering an impediment, the straight flexible tip may bend toward one of the vessel walls. Further, the straight flexible tip may bend and turn back upon itself upon encountering the impediment. As a consequence the straight flexible tip may encounter a sudden sharp turn which makes further navigation difficult.
Examples of successful devices that have been developed to address this need in the art are disclosed in U.S. application Ser. No. 10/719,764, filed Nov. 21, 2003, and entitled “Loop Tip Wire Guide,” now U.S. Pat. No. 7,520,881, which claims priority to U.S. Provisional Application Ser. No. 60/430,466, filed on Dec. 2, 2002; and in U.S. application Ser. No. 11/234,990, filed Sep. 26, 2005, and entitled “Steerable Loop Tip Wire Guide,” which claims priority to U.S. Provisional Application Ser. No. 60/614,908 filed on Sep. 30, 2004, all of which are incorporated herein by reference.
In the first application, a resilient loop and a closure member are affixed to the distal end of a wire guide. When this device is navigated through a body vessel and encounters an impediment, the distal end of the wire guide does not move relative to the remainder of the wire guide due to the presence of the loop and closure member. Instead, the loop deforms in response to the impediment. The resiliency of the loop creates a force opposing the impediment and directs the loop away from the impediment. Therefore, the remainder of the wire guide following the path created by the loop tip enables the wire guide to navigate around the impediment and continues along the interior of the vessel.
In the latter mentioned application, a steerable wire guide is provided that can be formed with or without a loop. The wire guide further includes a closure member to close the loop. In this configuration, the loop is static and makes a soft loop instead of a pointed end. The wire guide can be easily manipulated once inside the body vessel cavity. The wire guide deforms in accordance with the internal path of the body vessel. Yet, additional improved embodiments of wire guides are desirable.
The general purpose of the present invention overcomes problems in the prior art by providing an improved articulating steerable wire guide having multiple configurations yet sufficiently steerable to provide greater control by the user and safety when deployed. In situations where the point of treatment may be located in a side branch or beyond the bifurcation of the main vessel, there is a need for a wire guide that can be shifted and, durable as to be easily manipulated through the tortuous path. For this reason, a wire guide would be desirable to provide the user with greater ability of control. It would also be desirable to provide a steerable wire guide that can be turned in various degrees and configurations to provide access to any structure without substitution of any of its components.